Ant diversity marks restoration progress
When it comes to restoring grasslands, ecologists may have another way to evaluate their progress—ants.
South Dakota State University graduate student Laura Winkler collects specimens to determine the diversity of ant populations in restored grasslands in eastern South Dakota. Her research will help scientists track the progress of U.S. Fish and Wildlife Services restoration efforts.
The more diverse the ant population, the closer a restored section of grassland is to its original state, according to Laura Winkler, who recently completed her master’s degree in plant science, specializing in entomology, at South Dakota State University. When it comes to native grasslands, ants are “ecosystem engineers.”
Ecological role of ants
Ants play many ecological roles, Winkler explained. “They aerate the soil, cycle nutrients and play a role in plant defense and seed dispersal. Ants move more soil than earthworms, plus they are food for lots of reptiles and birds.”
Some ant species support colonies of plant-feeding insects, such as aphids or plant hoppers, even protecting them from predators. “It’s like having dairy cattle,” Winkler said. Through this technique, the ants consume the sugar-rich honey dew the aphids secrete, much as humans use cow’s milk. When the ants are in need of protein, they simply eat the aphids.
Ants also distribute organic matter by moving dead insects into the colonies and their dead nest mates away from the colonies, Winkler added.
Comparing restored, undisturbed grasslands
Winkler compared tracts of restored grasslands to undisturbed ones at three sites in eastern South Dakota--Sioux Prairie in Minnehaha County, Oak Lake Field Station in Brookings County, and Spirit Mound in Clay County. The U.S. Fish and Wildlife Service manages the restored areas, while the undisturbed area at Sioux Prairie is managed by the Nature Conservancy, Oak Lake by SDSU and Spirit Mound by the S.D. Game, Fish and Parks Department.
Originally from Des Moines, Iowa, she began working with ants as an undergraduate at Iowa State University focusing on how burning and grazing affect species diversity. Her SDSU graduate research assistantship on ant biodiversity and natural history was funded through the Meierhenry Fellowship. Her research adviser was entomologist Paul J. Johnson, professor of plant science.
Variation with age
The U.S. Fish and Wildlife Service sites that had once been crop or pasture land were restored anywhere from one to four years ago, according to Winkler. This involved taking the areas down to the bare ground and then seeding native grasses. Winkler used data from multiple sites taken over a one-year period.
As expected, the younger sites had fewer ant species, with the numbers and diversity increasing over time. The restoration areas at age 1 had seven different species, while at age 2, the number had increased to nine and by age 3 to 10 species, Winkler reported. She expected the fourth year restorations to be even closer to the 17 species present in the undisturbed remnants, but what she saw was a slight decrease to eight species.
“The drought last year and then a wet spring also affects that vegetation, what’s going to survive and how many of the ants are out foraging,” Winkler pointed out.
She suspects that management techniques may also have played a role. “Some sites may have been burned more frequently,” she noted, to control weeds.
“We’ve got a sneak peek of what can happen,” Winkler said, but more long-term research is needed. Based on other research, she anticipates that the restored areas should peak in terms of species diversity within seven to eight years.
Winkler also looked at how these ant species function. The younger restorations areas tend to have ants that are generalists who can go anywhere, but the older restorations tend to have more specialists, such as soil-dwelling ants, who are more particular about where they live, Winkler explained. The more dominant specialists push out some of the generalists.
“You’ll have ants everywhere,” she pointed out, but the greater the diversity, the more niches are being filled, and the more successful the restoration effort.
About South Dakota State University
Founded in 1881, South Dakota State University is the state’s Morrill Act land-grant institution as well as its largest, most comprehensive school of higher education. SDSU confers degrees from eight different colleges representing more than 175 majors, minors and specializations. The institution also offers 29 master’s degree programs, 13 Ph.D. and two professional programs.
The work of the university is carried out on a residential campus in Brookings, at sites in Sioux Falls, Pierre and Rapid City, and through Cooperative Extension offices and Agricultural Experiment Station research sites across the state.
Christie Delfanian | newswise
Waters are more polluted than tests say: Standard toxicity analyses come up short
30.11.2015 | Technische Universität München
Don't forget plankton in climate change models, says study
27.11.2015 | University of Exeter
Before the fluid of the middle ear drains and sound waves penetrate for the first time, the inner ear cells of newborn rodents practice for their big debut. Researchers at Johns Hopkins report they have figured out the molecular chain of events that enables the cells to make “sounds” on their own, essentially “practicing” their ability to process sounds in the world around them.
The researchers, who describe their experiments in the Dec. 3 edition of the journal Cell, show how hair cells in the inner ear can be activated in the absence...
Planet Earth experienced a global climate shift in the late 1980s on an unprecedented scale, fuelled by anthropogenic warming and a volcanic eruption, according to new research published this week.
Scientists say that a major step change, or ‘regime shift’, in the Earth’s biophysical systems, from the upper atmosphere to the depths of the ocean and from...
The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...
Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.
In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...
In laser material processing, the simulation of processes has made great strides over the past few years. Today, the software can predict relatively well what will happen on the workpiece. Unfortunately, it is also highly complex and requires a lot of computing time. Thanks to clever simplification, experts from Fraunhofer ILT are now able to offer the first-ever simulation software that calculates processes in real time and also runs on tablet computers and smartphones. The fast software enables users to do without expensive experiments and to find optimum process parameters even more effectively.
Before now, the reliable simulation of laser processes was a job for experts. Armed with sophisticated software packages and after many hours on computer...
30.11.2015 | Event News
25.11.2015 | Event News
17.11.2015 | Event News
30.11.2015 | Trade Fair News
30.11.2015 | Trade Fair News
30.11.2015 | Trade Fair News